Suppression of T and B cell responses by Pterodon pubescens seeds ethanolic extract.

The anti-arthritic property of hydro alcoholic extract of Pterodon pubescens seeds was previously demonstrated using the Collagen Induced Arthritis (CIA) in mice, the most similar arthritis experimental model to human rheumatoid arthritis. This disease is characterized by chronic inflamed joints resulting from exacerbated functions of macrophages and T and B lymphocytes. Anti-inflammatory and antinociceptive activities by ethanolic extract of Pterodon pubescens seeds (EEPp) have been also reported. This study describes the effects of EEPp on T and B lymphocytes functions from healthy mice. Delayed Type Hypersensitivity (DTH), in vivo antibody production, T and B lymphocyte proliferation and NO production were determined. Mice treated orally for 7 days with EEPp had inhibited 58% of B cell antibody production (10(-3) mg kg(-1) b.wt.) and 33% of the DTH response (10(-4) mg kg(-1) b.wt.), also reducing tissue leukocyte infiltration. EEPp (10(-2) mg mL(-1)) also inhibited in vitro T (89%) and B (68%) lymphocytes proliferation and NO production (53%) by macrophage cell line J774. The immunosuppression here described for EEPp supports its potential therapeutic use to control exacerbated humoral and/or cellular immune response as in autoimmune and chronic inflammatory diseases.

Eicosanoid-mediated proinflammatory activity of Pseudomonas aeruginosa ExoU.

As Pseudomonas aeruginosa ExoU possesses two functional blocks of homology to calcium-independent (iPLA(2)) and cytosolic phospholipase A(2) (cPLA(2)), we addressed the question whether it would exhibit a proinflammatory activity by enhancing the synthesis of eicosanoids by host organisms. Endothelial cells from the HMEC-1 line infected with the ExoU-producing PA103 strain exhibited a potent release of arachidonic acid (AA) that could be significantly inhibited by methyl arachidonyl fluorophosphonate (MAFP), a specific PLA(2) inhibitor, as well as significant amounts of the cyclooxygenase (COX)-derived prostaglandins PGE(2) and PGI(2). Cells infected with an isogenic mutant defective in ExoU synthesis did not differ from non-infected cells in the AA release and produced prostanoids in significantly lower concentrations. Infection by PA103 induced a marked inflammatory response in two different in vivo experimental models. Inoculation of the parental bacteria into mice footpads led to an early increase in the infected limb volume that could be significantly reduced by inhibitors of both COX and lipoxygenase (ibuprofen and NDGA respectively). In an experimental respiratory infection model, bronchoalveolar lavage (BAL) from mice instilled with 10(4) cfu of PA103 exhibited a marked influx of inflammatory cells and PGE(2) release that could be significantly reduced by indomethacin, a non-selective COX inhibitor. Our results suggest that ExoU may contribute to P. aeruginosa pathogenesis by inducing an eicosanoid-mediated inflammatory response of host organisms.

Acute and topic anti-edematogenic fractions isolated from the seeds of Pterodon pubescens.

We previously demonstrated that alcoholic extracts from Pterodon pubescens Benth. (Sucupira branca, Leguminosae) seeds exhibit anti-arthritic activity. In the present work we show that the oleaginous extract obtained from P. pubescens seeds (OEP) exhibits acute or topic anti-edematogenic activity when tested in carrageenan-induced paw edema or in croton oil-induced ear edema assays, respectively. Four fractions were obtained from OEP by sequential liquid-liquid extraction. The anti-edematogenic properties were predominant in the hexanic fraction, which was further fractionated by HPLC, yielding three sub-fractions (PF1.1, PF1.2 and PF1.3). PF1.1 and PF1.3 showed potent acute and topic anti-edematogenic activity. The PF1.2 sub-fraction, although not active in the carrageenan assay, exhibited a potent anti-edematogenic activity in the croton oil-induced ear edema. This sub-fraction shows a maximum efficacy similar to indometacin in a lower dose. The PF1.1 sub-fraction presented a complex mixture containing furane diterpene derivatives of vouacapan. PF1.2 consists of a single substance, geranylgeraniol, as determined by GC/MS and NMR, while PF1.3 contains farnesol.